| Summary: | 碩士 === 中臺科技大學 === 環境與安全衛生工程系碩士班 === 102 === Dispersing model analysis is the most often used in risk analysis and consequence simulation about chemicals’ leaking. But most scenario of tank leakage was just headline on single tank as well as the impact of itself. In real, most of chemical conpanies were not only installed single tank in storage site, there were many tanks equipped on storage area. And the result of chemical leaking was not only damaged the leaking tank itselft, but also possible to produce a series chain reaction of whole stoeage area,even caused a disaster of the company. Therefore; how to explore the multi-risk overlaps impact induced by dangerous and hazardous materials realse will be the key issue?.
This study was focus on the latex manufacturing company in Taiwan, butadiene (BD) and acrylonitrile (AN) were the major chemicals of its process. The northernest BD tank was 55 meters away from the southernest AN tank. Before simulation; we processed event tree analysis to discuss the possible effects induced by chemical leaking. A series simulation in various conditions such as tank size and location, wind direction and rate, chemical type and release dimeter etc would be conduted. The softway of dispersing model we used was ALOHA recommended by EPA of USA. Then we conducted the chain reaction derived by different consequence of simulation such as pool fire,jet fire, boiling liquid expanding vapor explsion (BLEVE), vapor cloud explosion and toxic diffusion etc. Following the results of chain reaction, we got the Multi-risk Overlaps Impact of each chemical leaking.
According study result, even though the northernest BD tank in southwest wind condition, 2 inches diameter pipeline broken induced a fire or explosion ,the following impact could not only cause other 3 BD tanks explosion and the southernest AN tank would be destroyed as well. In this scenario, the longest distance of 6 psi overpressure would reach 331 meters and the damaged range were 13000 m2. When the southernest AN tank in northeast wind condition, 2 inches diameter pipeline leaking induced a pool fire, it might cause a BLEVE, the diameter of thermal radiation of 37.5 kW/m2 was 111 meters and the cover area was 38455 m2. Besides; acrylonitrile was not a flammable material and it also was a toxic chemical, the large amount of AN would be release to air as AN wasm’t be ingired. Accroding to Probit equation; the death rate (in 10 min.) of 10%(433 ppm),50%
(597 ppm) and 99% (1026 ppm), the relative distance and area were 583 m and 24998 m2, 497 m and 31942 m2 and 373 m and 64579 m2. The toxic impact would not only cover the whole company and the adjacent areas of company, but the free highway and high speed railway would also be wounded even they were far form leaking site 250 m and 440 m relatively.
According to result; Multi-risk Overlaps Impact analysis method could be more completely discuss the possible impact and consequence of chemical leaking.. It’s not only can be more detail to identify to hazard , to assess risk and the possible impact and consequence of chemical of tanl leaking, but also to be a key reference to make the emergency response and to install the monitoring and mitigation system as well.
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